Swivel plug and receptacle



Ju y 15, 3 R. a. CUNNINGHAM ET 1,770,511

WU/EL PLUG" AND RECEPTACLE Filed April 13, 1929 JNVENTOR. EOLLA B. CU/Y/Z YYM I/I A TTORNEY.

Patented July 15, 1930 UNITED STATES PATENT OFFICE ROLLA B. CUNNINGHAM AND TUNIS J. CUNNINGHAM, OF TOPEKA, KANSAS SWIVEL PLUG AND RECEPTACLE Application filed April 13,

Our invention relates to improvements in swivel type plugs and receptacles for electric wiring.

The object of our invention is to provide a means of electrical connection in a threaded plug or wall receptacle whereby the attached cord is free to turn and electrical contact is always maintained.

Another'object of our invention is to provide a rotatable element trunnioned in a screw type plug or wall receptacle that rotates within a metal shell and maintains contact with the metal shell by reason of spring members bound to its surface and connected to one terminal of the plug cap and maintaining the other contact'by means of a pin trunnioned in a sleeve in the rotatable element, the sleeve being in connection with the other terminal of theplug cap and one end of the pin v functioning as the center contact in the screw shell socket connections. 1

A still further object of our invention is to provide a swivel connection for use in screw shell plugs and receptacle bodies, the

-' swivel being arranged to provide continuous electrical contact.

These and other objects will be hereinafter more fully explained.

Referring to the drawings:

Fig. 1 is a longitudinal section of a swivel plug of the separable type showing a plug cap in position for contact.

Fig. 2 is a plan view of the plug shown in Fig. 1 with the cap removed. 4 6

Fig. 3 is an elevation of the rotatable portion of the plug.

Fig. 1 is a cross section of the rotatable portion of the plug taken on line 44 in Fig. 3.

Fig. 5 is an elevation of the swivel plug with the cap in position.

Fig. 6 is a bottom view of the rotatable portion shown in. Fig. 3.

Fig. 7 is a longitudinal section of a wall outlet illustrating the method in which the rotatable portion, as shown in- Fig. 3, is positioned in a receptacle of this character.

A cylindrical member 1 fabricated of a dielectric substance and having a flange portion 2 at its upper extremity is apertured longitudinally by the rectangular slots 3 and 1929. Serial No. 354,855.

4 diametrically positioned. A metal sleeve 5 concentrically positioned in the member 1 is connected to the spring contact 6 in the slot- 4 as shown. A metal band 7 positioned on the surface of the member 1 has a plurality of spring finger portions 8 positioned in the recesses 9 of the member 1, the finger portions being formed as shown at A. The metal band 7 is connected to the prong 10 in the slot 3.

The c-ylindrical'member 1 is rotatably carried by the pin 11, positioned in and insulated from the metal shell 12, the latter being cylindrical in shape and threaded on its exterior surface for engagement with the standard threads of what is commonly known as a screw shell receptacle. The upper portion of the metal shell 12 has firmly positioned thereon an annular ring of dielectric material 13, the periphery of which is serrated asshown at B to provide a grip for the hand in turning the threaded shell into a socket. The metal shell is closed at the bottgm as shown and positions the pin 11 at this point, the latter being insulated from the shell by the insulating bushing 14. The sleeve 5 and its strap connection are insulated from the bottom of the metal shell by the insulating disc 14. J i

The fingers 8 are continually in contact with the shell 12 as shown at C. The metal tube 5 is continually in contact with the pin s0 11,the lower portion of which forms the center contact of the plug in screw shell fittings. The member 1 is held in position on the pin 11 by reason of a washer 15 and nut 16, the latter threadedly engaging the pin 11 as 8 shown. The nut 16 on the pin is arranged to prevent the movement of the member 1 in an axial direction with regard to the pin but allows the member 1 to rotate freely about the pin, the tube 5 acting as the bearing on the pin and the fingers 8 being in constant slidable engagement with the metal shell. In this manner any twist occurring in the cord 17 connected to the plug cap 18, whose prongs v 19 are in contact with the contacts 6 and 10 in the member 1, will rotate the member 1 thereby relieving any strain on the cord that might exist. Electrical contact remaining intact at all times.

Referring to Fig. 6 which is a bottom View of the rotatable member 1, the strap connections between the band 7 and the contact 10, and between the tube 5 and the contact 6 are shown at D and E respectively.

Referring to Fig. 7 which is a longitudinal section of a wall outlet, the member 1 is shown rotatably mounted in the cylindrical shell 20, the latter being connected to the binding post 21 by the strap 22. The pin 11, in this case, is connected to the binding post 23 by the strap The arrangement of the rotatable body 1 as shown in Fig. 3 with its component parts is exactly the same in Fig. 7. The shell in Fig. 7 takes the place of the shell 12 in Fig. 1 and the pin 11 makes contact to the binding post 23 instead of direct- 1y to a receptacle contact, as it would in the screw shell connection. The arrangement shown in Fig. 7 is an application of the rotatable member 1. in exactly the same manner as itis shown in Fig. 1 with the exceptions and modifications herein described. The con stant contact of the metal tube with the center pin 11 and the constant contact of the fi ngers 8 with either the metal shell 12 or 20 insure continuous flow of current whether the plug is stationary or rotating.

Such modifications maybe employed as lie within the scope of the appended claims and what we do claim as new and desire to secure by Letters Patent is:

1. A swivel type plug connection for electrical circuits comprising a rotatable element as a receptacle positioned in a metal shell and rotatable therein. and having fingers positioned on its periphery for contact with the metal shell and a sleeve engaging a pin at its center for contact and the said fingers and said sleeve providing continuous connection between the source of energy and the plug cap during rotation of the element.

2. In a swivel type receptacle for plug cap electrical connections. a rotatable member composed of an insulating substance and a metal shell within which said member rotates. the rotatable member slotted longitudinally for the reception of the prongs of a plug cap and having spring contacts therein, a plurality of spring fingers positioned on the periphery of the rotatable member to which one of the spring contacts is connected, a sleeve centrally disposed in the rotatable member to which the other spring contact is connected, said sleeve acting as a bearing, apin centrally positioned and insulated from the metal shell and engaging in the said sleeve for rotatable contact and the said spring fingers providing slidable electrical contact with the said metal shell and the said sleeve providing an electrical contact with the said pin.

3. In a swivel plug for electrical connections of the screw shell type to accommodate plug caps, a cylindrical shell closed at one end and threaded on its exterior surface for engagement with screw shell receptacles, a cylindrical body formed of a dielectric substance rotatably mounted within the shell and trunnioned theiein' by a pin. the pin firmly positioned in the end of the metal shell and insulated therefrom and extending into and positioning the cylindrical body, a metal sleeve in the said cylindrical body slidably engaging said pin, a plurality of spring fingers positioned on the periphery of the cylindrical body in contact with the metal shell an d a spring contact positioned in a longitudinal slot in the cylindrical body in electrical connection with said spring fingers, another spring contact positioned in a longitudinal slot in the cylindrical body electrically connected to the said pin by said sleeve, and the end of the said pin functioning as the center contact in screw shell receptacles.

4.- In a swivel type receptacle for plug caps, a receptacle, cylindrical in form and having contacts positioned in longitudinal slots in the receptacle to engage the prongs of plug cap, the receptacle being constructed of non-conducting material, a pin member positioned in a body and trunnioning the said receptacle, a metal shell positioned in the body cylindrical in form and co-axial with the receptacle, a metal sleeve acting as a bearing in the receptacle for the said pin member and providing a contact from one of the contacts to the pin, a metal band positioned on the periphery of the receptacle, a plurality of fingers integral with the band and bearing on the metal shell and providing a connection from the other of the contacts to the metal shell substantially as shown.

5. In a swivel type receptacle, a cylindrical rotor formed of an insulating substance and having slots therein, spring contacts positioned in the slots for engagement with the prongs of a plug cap, the rotor being trunnioned at its center by a pin, the said pinbearing in a metal sleeve, the said sleeve centrally positioned in the rotor, a band positioned on the surface of the rotor, a plurality of spring fingers attached to the band and held in position against a metal shell, the band electrically connected to one of the said spring contacts and the. sleeve electrically connected to the other of the said spring contacts.

In testimony whereof we atlix our signatures.

ROLLA B. CUNNINGHAM. TUNIS J. CUNNINGHAH. 

